128 



Report on Trials of Plows. 



sticks used were on the principle of the double mould-board; 

 they threw off the earth on each side. The next step was to hew 

 off one side of the stick, so as to throw out the earth only on one 

 side, approximating to a single mould-board. Then the plow 

 became a simple wedge, the land side being nearly parallel with 

 the line of the plow's motion, the other moving the furrow slice 

 to the right, but leaving the furrow standing on edge. Then the 

 wedge was gradually twisted so as regularly to invert the furrow. 

 Jefferson and Small discovered the importance of straight lines 

 running from the sole to the top of the share and mould-board. 



J^iff. 73. 



Colonel Pickering was the first to discover the importance of a 

 straijrht line running; from the front to the rear. Jethro Wood 

 discovered that all the lines running from front to rear should be 

 straight. Mr. Knox first discovered a method of laying down 

 all the lines of a plow on a plane surface. Mr. John Mears was 

 the first to discover the importance of centre draft, and pointed 

 out the practical means of attaining it by the inclination of the 

 land side inward. 



Aaron Smith was the first to adopt two plows to work well 

 together, one of which threw two or three inches of the surface 

 into the bottom of the preceding furrow, and the other covered 

 it with the lower earth. 



Finally, Governor Holbrook has invented a method by which 

 plows of any size may be made symmetrically, either convex or 

 concave, in such a way as to insure the complete pulverization of 

 the soil. 



We believe that we have been the first to announce that the 

 great object in all plows is to form the curve in such a way as to 

 make all the parts of the furrow slice to travel with different 



